New Technology Unveils Massive Illegal Fishing by Dark Fleets in North Korea, What Next?

International collaboration and new technology shows unprecedented picture of fishing activity in North Korea, calls on nations to take action

In the 30th issue of Science Advances Global Fishing Watch, along with 13 other co-authors, published a study revealing widespread illegal fishing in North Korean waters across 2017 and 2018. Hundreds of large, industrial vessels originating from China likely violated United Nations (U.N.) sanctions and caught almost half a billion dollars worth of Pacific flying squid. In addition, we found about 3,000 smaller, North Korean artisanal vessels, almost all of which operated illegally, fished in Russian waters in 2018.

When we finalized the 2017-2018 analysis to submit our paper, the 2019 squid season had not yet begun. Nearly two years later in 2020, we are left wondering whether or not the illegal fishing continued. And if so, what exactly needs to be done to stop this illegal activity?

To identify fishing activity, we drew on four forms of satellite data: 

  • Vessel GPS data from the automatic identification system (AIS), which allows us to monitor the movements of the vessels that broadcast their positions. 
  • Optical imagery from Planet, which provides visual confirmation of the vessels. 
  • Nighttime optical imagery, which reveals squid vessels that use bright lights to attract catch.
  • Satellite radar, which allows us to count industrial vessels even under overcast skies. 

Working with our partners, we obtained imagery for 2019 and 2020 and repeated our analysis. The results for 2019 can be read here, and some analysis for 2020 can be seen below in this blog post. The key takeaway is that illegal fishing has continued unabated: 2019 was extremely similar to previous years, and in 2020 large foreign fleets have already started fishing in North Korean waters. 

The figure below (an updated version of Figure 4C from Park et al. 2020) shows the number of industrial fishing vessels originating from China in North Korean waters across three years. Fewer vessels were detected in 2019 than in 2017, but more than were observed in 2018. We counted at least 790 unique vessels originating from China operating a total of about 82,000 days in North Korean waters, likely catching about US $240 million worth of squid. 

Figure 1. (A) Industrial fishing vessels originating from China detected in North Korean waters using satellite imagery, 2017-2019. Two types of vessels were detected: pair trawlers that drag huge nets between them and large single vessels that use bright lights to lure squid to the surface at night. The South Korean coast guard also provided on-the-water observation of vessels originating from China crossing through South Korean waters into North Korea. (B-D) Comparison of the number of vessels, the estimated total catch based on satellite detections, and the estimated total fishing days based on coast guard counts, 2017-2019. 

There were slightly fewer North Korean vessels in Russian waters in 2019 than in 2018. However, with at least 2,000 vessels and 150,000 likely total days of fishing, the fishing activity in 2019 was still higher than 2017 or any previous year. The number of North Korean vessels washed ashore in Japan with human remains or no crew, often referred to as ghost boats, is highly correlated with the number of the North Korean vessels in Russian waters and the number of days these vessels fished. This trend suggests that the number of so-called ghost boats found on Japanese shores is related to the number of ill-equipped North Korean vessels fishing far into Russian waters. 

Figure 2. (A) Artisanal North Korean vessels fishing in Russian waters, 2015-2019. Small-scale North Korean vessels are detected using nighttime optical imagery. They are known to use far fewer light bulbs on their squid fishing boats, allowing us to distinguish them from other industrial vessels. (B-D) Comparison of the number of vessels, the estimated total fishing days based on satellite detections, and the number of ghost boats reported in Japan, 2015-2019. 

The 2020 squid fishing season started in May and will continue through to December. The technologies applied in our Science Advances paper can be used to monitor these vessels as the season progresses. We have started processing some 2020 data and can already see over 600 pair trawlers originating from China operating in North Korean waters (see Fig. 3).

Figure 3. Processed images from each of the four satellite technologies. We detected over 600 pair trawlers using radar imagery on May 28, 2020 while daytime optical imagery detected consistent but fewer numbers of vessels due to an incomplete coverage. AIS data shows their fishing grounds are similar to the previous years. There are very few lighting vessels detected so far. Lighting vessels are known to operate in North Korean waters later in the fishing season. 

Without decisive action, large-scale illegal fishing will likely continue in these poorly-monitored waters, hastening the decline in squid stocks and resulting in other tragic consequences, particularly for North Korean artisanal vessels forced to fish further from home. The U.N. is key to resolving this illegal fishing and humanitarian crisis. The U.N. Security Council established a Committee to oversee the sanctions measures imposed against North Korea. A Panel of Experts, under the sanctions Committee, reviews the status of sanctions and noncompliant activities including foreign fishing, and produces bi-annual reports. In the reports published in 2019 and 2020, member countries anonymously reported to the Panel that foreign fishing in North Korea was taking place. However, they estimated that about 200 vessels from China were in operation in North Korean waters, far smaller than the number we detected, and the report provided little evidence to substantiate their claim. China refuted the allegation maintaining that “Chinese authorities have prohibited ocean fishing operations in [North Korea’s] sea areas,” and “some ships were operating solely in coastal areas of China.” Upon other suspected violations, China dismissed the claims as being “baseless” and requiring “more evidence.” 

Constructive international dialogue and action on illegal fishing will rely on robust, science-based information that all parties can trust. It also demands that regional management measures include compulsory use of the AIS for all fishing vessels flagged to China (which our study suggests is not being followed), increased sanctions for unlawful fishing activity, and continued bilateral dialogue and collaboration. Efforts to develop more cohesive, cost-effective, and comprehensive stock management will be thwarted as long as the dark fleet – vessels that do not publicly broadcast their location or appear in public monitoring systems – continue to prevail in the region.

To turn the tide, collaboration at a multilateral level is essential for ensuring the sustainable use of Pacific flying squid and further addressing challenges of transboundary fisheries management. Informed decisions through scientific findings provided by satellite monitoring technologies are vital to advancing collaboration. Global Fishing Watch stands ready to support this process through objective, credible, and scientific information. 

We hope relevant governments can draw on our analysis to take concrete action to prevent illegal fishing, and we urge nations involved in these waters to conduct further investigation with regard to who should be held responsible for breaching international and domestic regulations. Moving forward, we remain committed to helping governments monitor their waters and fishing vessels more effectively. And our support is not only for this region but also for other regions around the globe affected by illegal fishing. 

Download the 2019 analysis paper.

David Kroodsma is the director of research and innovation at Global Fishing Watch. Jaeyoon Park is a senior data scientist at Global Fishing Watch.

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